William s



(No Model) W. S. HUGHES.

Slide Valve.

No. 242,929. Patnted June 14,1881.

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I WITNBSES: INVENTOR! ATTORNEYS.

UNITED STATES PATENT OFFICE.

WILLIAM S. HUGHES, OF LONG ISLAND CITY, NEW YORK.

VALVE.

SPECIFICATION forming part of Letters Patent No. 242,929, dated June 14,1881.-

Application filed April 27, 1881. (No model.)

To all whom it may concern:

Be it known that I, WILLIAM S. HUGHES, of Long Island City, in thecounty of Queens and State of New York, have invented a new and ImprovedSlide-Valve, of which the following is a full, clear, and exactdescription.

The main object of this invention is to reduce or prevent the noise madeby exhauststeam of engines, which has heretofore been attempted by theuse of inuffles and similar devices. With the ordinary link-motion andslide-valve used on locomotives the exhaustedge of the valve mustbemoved the length of lap and lead before the piston receives steam fromthe direction in which it has been movin g. in other words, theexhaust-opening hegins before the piston finishes its stroke, and beforethe steam has fully expanded. The exhaust being also opened suddenly bythe quick movement of the eccentric, a wasteful anddisagreeableexplosion of steam from the cylinder takes place. To removethis difficulty I have heretofore combined devices with the valve-cavityfor obtaining a gradually-increasing opening, so that theexhaust'previous to the completion of the piston-stroke is limited, andthe exhaust-steam, instead of being allowed to explode, is graduallyreleased, and without back-pressure.

The present invention is a variation of the invention shown in anapplication for Letters Patent heretofore made by me; andit consists ina valve having the sides of its exhaust-cavity'graduated to give anopening gradually increasing in depth, in eontradistinetion to devicesupon the face of the valve that cut off the opening more or less.

In the accompanying drawings, Figure 1 is a face view of a slide-valveembodying my invention, and Fig. 2 is a cross section of the same.

Similar letters of reference indicate corre spondin g parts.

A is the slide-valve, having exhaust-cavity a on the underside.

B is the valve-seat, having steam-ports b b and exhaust-port c, asusual.

The sides of the exhaust-cavity a. are made in step-like form, so thatthe depth increases as the valve moves forward, thereby giving anenlarged space for exhaust. The first opening being small and indirect,the exhaust-steam is baffled and detained, and the exhaust, insteadnoiseless passage of steam to theexhaust-port and smoke-stack. There\villbe no back-pressure, for the reason that the first outlet ofexhaust-steam takes place before the live-steam ports are opened, andthe exhaust is fully open when the piston commences its return-stroke.

In Fig. 2 a perforated diaphragm or partition, (7, is shown as fitted inthe exhaust-cavity, for the purpose of dividing the exhauststeam afterit has entered the cavity. This partition may be dispensed with.

The construction may be modified to obtain regulation of theexhaust-opening, and indirect passages for the steam by variations indepth.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. A slide-valve having its exhaust-cavity a formedwith sides graduated in depth, wheredepth from the edge is obtained,substantially as shown and described.

2. The slide-valve having the sides of its exhaust-passage made instep-like form, in combination with the perforated partition 61 therein,substantially as and for the purpose set forth.

WILLIAM S. HUGHES.

Witnesses GEo. D. WALKER, O. SEDGWICK.

by an exhaust-opening gradually increasing in' of being an explosion,becomes an almost

